122001-26-7Relevant academic research and scientific papers
Copper-mediated oxidative [3 + 2]-annulation of nitroalkenes and pyridinium imines: Efficient synthesis of 3-fluoro- A nd 3-nitro-pyrazolo[1,5-: A] pyridines
Ioffe, Sema L.,Motornov, Vladimir A.,Nelyubina, Yulia V.,Nenajdenko, Valentine G.,Tabolin, Andrey A.
, p. 1436 - 1448 (2020)
An efficient route to pyrazolo[1,5-a]pyridines by Cu(OAc)2-promoted oxidative [3 + 2]-annulation of nitroalkenes with in situ generated pyridinium imines is developed. The reaction with α-fluoronitroalkenes enables the first preparative synthesis of 3-fluoro-pyrazolo[1,5-a]pyridines. Cycloaddition with α-unsubstituted nitroalkenes provides access to 3-nitro-pyrazolo[1,5-a]pyridines in excellent yields. A broad transformation scope was demonstrated. Both electron-rich and electron-deficient nitroalkenes as well as different aminopyridinium salts can be used for the assembly of the target pyrazolo[1,5-a]pyridines. The related aza-heterocycles, namely, pyrazolo[1,5-a]pyrazines and pyrazolo[1,5-b]pyridazines, were successfully prepared via the present methodology. The possible mechanism of the reaction is discussed.
-Annulation of pyridinium ylides with 1-chloro-2-nitrostyrenes unveils a tubulin polymerization inhibitor
Aksenov, Alexander V.,Aksenov, Dmitrii A.,Aksenov, nicolai A.,Arutiunov, nikolai A.,Betancourt, Tania,Du, Liqin,Grishin, Igor Yu.,Kirilov, nikita K.,Kornienko, Alexander,Rubin, Michael,Wang, Huifen,pelly, Stephen C.
, p. 7234 - 7245 (2021/08/30)
Indolizines and pyrazolo[1,5-a]pyridines were prepared via [3 + 2]-cycloaddition of pyridinium ylides to 1-chloro-2-nitrostyrenes. The synthesized molecules were evaluated for antiproliferative activities against a BE(2)-C neuroblastoma cell line with several compounds decreasing the viability of cancer cells. Indolizine 9db showed higher potency than that of all-trans-retinoic acid, an approved cancer drug. Mechanistically, it was found to inhibit tubulin polymerization and it is thus proposed that the discovered chemistry can be exploited for the development of novel microtubule-targeting anticancer agents.
Substrate selective synthesis of pyrazolo[1,5-a]pyridines through [3 + 2] cycloaddition of N-aminopyridines and β-nitro styrenes
Ravi, Chitrakar,Chandra Mohan, Darapaneni,Naresh Kumar Reddy,Adimurthy, Subbarayappa
, p. 42961 - 42964 (2015/05/27)
Synthesis of (hetero)aryl pyrazolo[1,5-a]pyridines through [3 + 2] cycloaddition of N-aminopyridine with β-nitrostyrenes followed by in situ denitration and oxidation under metal-free, mild conditions are described.
